Granulating device



Aug. 29, 1967 s GRANULATING DEVICE 15 Sheets-Sheet 1 Filed Jan. 28, 1965ozcZEwA INVENTOR HEiqZ LIST AGENT Aug. 29, 1967 H. LIST 3,337,913

GRANULATING DEVI CE Filed Jan. 28. 1965 5 Sheets$heet INVENTOR 20b HEINZLIST BY x AGENT Aug. 29, 1967 H. LIST GRANULATING DEVICE 3 Sheets-Sheet3 Filed Jan. 28, 1965 FIG. 3

INVENTOR HEINZ LIST AGENT United States Patent GRANULATING DEVICE HeinzList, Pratteln, Switzerland, assignor to Buss AG, Basel, SwitzerlandFiled Jan. 28, 1965, Ser. No. 428,808 Claims priority, applicationSwitzerland, Feb. 1, 1964, 1,201/ 64 9 Claims. (CI. 18-12) The presentinvention concerns a granulating device for reducing a mass of materialto granular or particulate form, which has a material-working member,more particularly a continuously operating worm co-operating with radialoutlet nozzles of the surrounding housing.

Granulating devices with worm mechanisms are known which serve for themixing, kneading and extruding of plastic substances, especiallysynthetic materials. In these devices the revolving worm works andcompresses the product to be granulated in the axial direction through aplate having nozzles, and which is fitted with a rotating knife whichcuts the strands of material extruded from the nozzles into granular orparticulate form. Many of the newer products cannot be worked withoutdifficulty with such a granulating device as the sticky granulateadheres to the knife and thereby lowers its etficiency.

Furthermore known granulating devices have the additional disadvantagethat only a small part of the surface contacted by the knife is utilizedand further that the granulate reaches the reception chambers in lumps.Also, the material particles are uneven as a uniform heating of a nozzleplate perforated with axial bores is hardly possible.

The object of the invention is to provide a granulating device in whichthe disadvantages cited above are avoided. More particularly,satisfactory working of sticky products in continuous operation is to beobtained wherein the material particles do not adhere, neither to theknife nor to the inner wall of the reception chamber,

The granulating device according to the invention has a material-workingapparatus, more particularly a continuously operating worm inside ahousing having outlet nozzles. These nozzles, arranged at the oulet endof the worm, are disposed in a hollow body provided with substantiallyradial bores. Revolving cutting members are provided which contact theouter surface of the hollow body with their cutting edges.

The hollow body is preferably of a cylindrical or frustoconical shape.

According to a preferred embodiment, rotating fan blades are associatedwith the cutting members, which produce a stream of air whichadditionally accelerates and cools the particles of material which isoutwardly centrifuged by the cutting members.

It is further contemplated to provide substantially axial bores in thehollow body, through which uniform heating is obtained. For this purposea heating medium may be circulated in the bores or electrical heatingmeans may be arranged therein.

An exemplary, preferred embodiment of the invention is shown in theaccompanying drawings in which FIG. 1 is a partly sectional sideelevational View of one embodiment of the granulating device accordingto the invention;

FIG. la is a partial sectional view illustrating a cylindrical aperturedmember as a modification of the conical member shown in FIG. 1; I

FIG. 1b is another partial sectional view showing optional drive meansfor oscillating the cutting devices together with the bearing case;

FIG. 2 is a partly sectional view of the major inner components, takenalong line 11-11 of FIG. 1, with the knives and the fan bladesinterconnected;

Patented Aug. 29, 1967 FIG. 2a is a view similar to that of FIG. 2 butshowing a modification wherein the knives are supported for rotationseparate from that of the fan blades, also showing a separate supportfor the latter; and

FIG. 3 is an end view of the granulating device, taken from theright-hand side of FIG. 1.

The illustrated granulating device has a housing 1 in which amaterial-working member is disposed in the form of a worm 2 capable ofcontinuous operation. The housing 1 is fixed to the floor or ground in aconventionalmanner, eg by the intermediary of a foundation or base 1a,as shown in FIG. 1. A conventional drive is shown at 2a for the worm 2.A plurality of outlet nozzles is arranged at the right-hand end of thehousing 1, as viewed in FIG. 1, being constructed as a hollow body ofrotation in the form of an outlet support 4 and a conical aperturedmember 5 (FIG. 1). Stirrup clamps 3 and '3' are provided to secure theoutlet nozzle support 4 onto the housing 1. The apertured member may begiven a cylindrical shape, as shown at 5 in FIG. 1a while FIG. 1 showsthe conical member 5.

As can be seen from FIG. 1 the conical apertured member 5 is providedwith radially aligned apertures 6 to allow passage of the material to begranulated. Longitudinal bores 7 serve to accommodate a heating fluid ormedium for the apertured member 5. An extruder 8', forming the extensionof a trunnion 8, extends into the interior of the apertured member andhas bores 8" which form extensions of the bores 7.

The trunnion 8 is flanged to the end flange of the nozzle support 4(e.g. by way of a number of circumferential bolts). Thus the trunnion 8is arranged coaxially with the worm 2, and it carries a rotatablebearing case 11 by means of bearings 9 and 10. The feed of the heatingmedium to bores 7, 8" takes place by means of a pipe 12 attached to themouth of the bore 7 while a pipe 12 is provided for allowing the heatingmedium to be discharged therefrom. The heating medium which enters thelongitudinal bores 7 through pipe 12, is fed through the bores 8" of theextruder 8 and flows back into the external heating system throughfurther longitudinal bores 7 and pipe 12'. The heating system is notshown in the drawing.

In place of fluid heating, electrical heating could be provided by meansof electric heating elements disposed in the bores 7, 8.

Preferably two cutting devices are provided, including knife arms 13carried by the bearing case 11, radially disposed and extending in theaxial direction, each of the arms 13 carrying a knife 14 and a fan blade15 (see also FIG. 2). For the sake of clarity, FIG. 1 only shows onesystem of elements 1315. The knives may be adjustably arranged relativeto each other in the axial direction (not shown). The arrangement of theknives 14 is such that during rotation of the bearing case 11 theycontact the surface of the radial apertures 6, member 5 in the region=of the apertures thereof.

time cooling and setting of the material particles takes.

place.

A reception chamber for the material particles is shown at 20 (see FIGS.1 to 3). This chamber 20 surrounds the apertured member 5 along with therotating knives 14 and the fan blades 15. It is suggested to providelateral rotating walls 16 and 16' attached to the knife arms 13. In FIG.1, the right-hand side of the chamber 20 is shown with releasable ordetachable flanged portions, for cleaning and maintenance purposes ofthe inner mechanism.

The bearing case 11 is provided with a bore 18 which connects withcorresponding bores 18 in the knife arms 13, these bores terminating inoutlet openings or spraying nozzles 19 at the outlets and adjacent therespective fan blades 15. Lateral yokes or brackets attached to theouter walls of the reception chamber 20 (see FIG. 3) hold a stufling box17 which is thus connected with the conical flange of the nozzle support4. A liquid or gaseous medium is fed into the stuffing box 17 through anappropriate inlet pipe 18a, thence through the bores 18 of the bearingcase, the corresponding bores 18 in the knife arms 13 andto the sprayingnozzles 19 adjacent the fan blades 15 so as to form a protective filmthereon, as well as on the inner wall of the reception chamber 20, whichprevents the material particles from adhering thereto.

The medium should conveniently be guided as near as possible to thecutting edges of the knives 14. In this way the affected surface will beextensive and the cooling of the knives improved.

A V-belt 21 and a conventional drive 11a are provided to drive thebearing case 11 (FIG. 1) together with the attached cutting devices.

As can be seen from the drawing the bearing 10 along with the bearingcase 11 supported thereby is subject to the action of a compressionspring 22 which urges the bearing case along with the knives 14 towardsthe righthand side in FIG. 1.

An adjustment nut 23 with a lock nut 24 (see also FIG. 3) serves as anabutment against this displacement. By adjustment of the nut 23 the playbetween the knives 14 and the apertured member may be adjusted duringoperation as desired.

Further nozzles 25 (FIGS. 1, 2 and 3) are provided for additionallyspraying the inner walls of the reception chamber 20.

In one preferred embodiment, illustrated in FIG. 1, two diametricallyopposed knives 14 are shown, as a matter of example, so that on eachrevolution of the case 11 each strand of material issuing from theapertures 6 will be out twice. Should only a single cut be required totake place at a similar cutting speed, the knives can be provided suchthat their length corresponds to only half the length of the outerconical surface line of the apertured member 5 as shown at 14 in themodified partial view of FIG. 1a. On the other hand, it is also possibleto provide additional knife arms, for example four or six (notillustrated.)

It is further possible to use the above-described axial adjustability ofthe device not only for a change in the play of the knives 14 but toprovide an additional oscillating drive in the axial direction. Such adrive is shown, as a matter of example, in FIG. lb, at 11b, with alinkage 11c connecting the mechanism to the bearing case 11. i Incombination with the cylindrical apertured member 5 of FIG. 1a, theoscillatory movement produces a drawing cut whichis advantageous withcertain products. If the conical apertured member 5 of FIG. 1 is used,the length of the material particles can be varied by the axialoscillating movement of the cutting device. In this way the knife ismade to jump over one or more rows of nozzles or apertures 6 beforecutting the next row.

It is shown in the modification of FIG. 2a that it is also possible tomount shorter fan blades 15 on a separate support or crown 15asurrounding and radially spaced from the cutting knives 14, and to drivethe crown independenly therefrom the drive for the knives. In this casethe fan blades 15 rotate in the same plane as the knives 14, the volumetraversed by the blades being concentric with and surrounding the volumetraversed by the cutting device constituted by the knives. FIG. 2ashows, in an exemplary manner, drive means 15b, in the form of amotor-driven pinion, acting upon a toothed outer rim of the support orcrown 15a. The latter may be supported by inner bearings, as shown.

It should also be explained that under certain conditions it may beconvenient to build in additional fan blades between the blades 15associated with the cutting members 14, which are disposed and drivenindependently from the knife arms 13. 7

Finally it should further be pointed out that when working stickymaterial, the surfaces of the blades 15, 15 should be kept as small aspossible. An additional air stream should be produced in this case bythe provision of an additional fan which is arranged outside thereception chamber 20 and effects exhaustion as well as cooling of thematerial particles. As a matter of example, FIGS. 2 and 3 show such afan at 20a, for producing the additional air stream for the materialparticles. Again as a matter of example, an outlet or discharge 20b hasbeen shown in the drawings for the material particles.

What I claim is:

1. A granulating device comprising, in combination, a

material-working apparatus in the form of a rotatable worm having outletmeans arranged at the outlet end of said apparatus, said outlet meansbeing in the form of a channeled and apertured member havingsubstantially radial bores for the passage of the material upon rotationof said worm, at least one rotatable cutting member supportedsubstantially coaxially with respect to said apparatus and on the sideof said apertured member facing away therefrom, each cutting memberhaving a cutting edge in linear contact with a portion of the outersurface of said apertured member, and at least one rotatable fan bladeconnectable with a respective cutting member, said cutting members andsaid fan blades when aligned presenta ing a unitary curved profiletangentially contacting said outer surface of the apertured member.

2. The granulating device as defined in claim 1, wherein said aperturedmember has therein substantially axial bores intermediate said radialbores, spaced apart and independent therefrom, and adapted for operativeassociation with heating means for the material by the intermediary ofthe wall of said apertured member.

3. The granulating device as defined in claim 1, further comprisingfirst drive means for rotating said worm, a rotatably journaled bearingcase supporting said cutting members and said fan blades, and seconddrive means for rotating said bearing case independently from said firstdrive means.

4. The granulating device as defined in claim 3, wherein said bearingcase is mounted coaxially with respect to said worm, further comprisingadjustable abutment means in operative connection'with a portion of saidbearing case, and biasing means for urging said bearing case toward saidabutment means and for urging said cutting members axially away fromsaid worm, so as to adjust the play between said cutting members andsaid outer surface of the apertured member.

V 5. The granulating device as defined in claim 3, further comprisingthird drive means for axially oscillating said bearing case andcyclically altering the play between said cutting members and said outersurface of the apertured member.

6. The granulating device as defined in claim 3, further comprising ahousing for said apparatus, said apertured member forming the outlet endof said housing intermediate said worm and said bearing case, saidcutting members having therein outlet apertures facing away from saidapertured member, a conduit system operatively connected with saidoutlet apertures for allowing spraying fluid to be fed to the vicinityof said fan blades, and a reception chamber for the material,surrounding and spaced away from said cutting members.

7. The granulating device as defined in claim 6, wherein said aperturedmember has at least two substantially concentric rows of said radialbores, and the length of at least one of said cutting edges, contactingsaid outer surface of the apertured member, is shorter than the linearlength of two adjoining rows of radial bores so that said one cuttingedge will pass over only one of said two rows.

8. The granulating device as defined in claim 1, further comprisingfirst drive means for rotating said worm, a.

.rotatable crown surrounding and radially spaced from References Citedsaid cutting members, for supporting said fan blades UNITED STATESPATENTS separately from said cutting members, second drive means 2 422 40 1947 Gordon 13 12 for rotating said cutting members alone, and thirddrive 5 2,524,751 10/1950 Berger 1812 means for rotating said crownindependently from said 219471654 8/1950 Chapman 83-98 X second drivemeans. FOREIGN PATENTS 9. The granulating device as defined in claim 8,further 649,314 10/1962 Canadacomprising fan means for producing an airstream in 10 1148154 6/1957 France the vicinity of said cutting members-WILLLAM J. STEPHENSON, Primary Examiner.

1. A GRANULATING DEVICE COMPRISING, IN COMBUSTION, A MATERIAL-WORKINGAPPARATUS IN THE FORM OF A ROTATABLE WORM HAVING OUTLET MEANS ARRANGEDAT THE OUTLET END OF SAID APPARATUS, SAID OUTLET MEANS BEING IN THE FORMOF A CHANNELED AND APERTURED MEMBER HAVING SUBSTANTIALLY RADIAL BORESFOR THE PASSAGE OF THE MATERIAL UPON ROTATION OF SAID WORM, AT LEAST ONEROTATABLE CUTTING MEMBER SUPPORTED SUBSTANTIALLY COAXIALLY WITH RESPECTTO SAID APPARATUS AND ON THE SIDE OF SAID APERTURED MEMBER FACING AWAYTHEREFROM, EACH CUTTING MEMBER HAVING A CUTTING EDGE IN LINEAR CONTACTWITH A PORTION OF THE OUTER SURFACE OF SAID APERTURED MEMBER, AND ATLEAST ONE ROTATABLE FAN BLADE CONNECTABLE WITH A RESPECTIVE CUTTINGMEMBER, SAID CUTTING MEMBERS AND SAID FAN BLADES WHEN ALIGNED PRESENTINGA UNITARY CURVED PROFILE TANGENTIALLY CONTACTING SAID OUTER SURFACE OFTHE APERTURED MEMBER.